Scan tool Diagnosics

1. Scan Tool Data

1.1       Find a vehicle which is appropriate for the scan tool.

1.2       Connect the scanner, power it on, follow the instructions and input the correct vehicle information it asks for so you can view the data.

1.3       Find the data for the information listed on the next page. Turn engine on to idle. Fill in the letters used to label the information and the value of that data. (For example, engine load information may be found under MAP, with a value of 3.6, listed in volts) Note: not all vehicles will support all information, just find as much as you can. If the engine won’t run, input the information with the key on, engine off.

Type of information (PID = Parameter Identification)	Letters to describe it E.g. TPS	Value of data	Units for data E.g. volts
Engine Load (how much air comes in)	Intake	15%	Percentage
Engine RPM	RPM	725	Revolutions per minute
Throttle angle	TPS	0.96v	Voltage
Engine coolant temperature	ECT	33°C	Degree Celsius
Intake air temperature	IAT	3.73
Fuel Injection opening pulse	FIOP	4.71	Ms
Transmission select position	-
Vehicle Speed	-	0	KM/H
Oxygen sensor(s)	O2	0.10-0.70v	Voltage
Fuel Trim	-
Idle control	IAC	43%	Percentage
Power steering Load		0.02v	Voltage
Air conditioning condition	AC	3.91	Voltage
Exhaust Gas Recirculation (EGR)
Fuel Evap or Purge condition
Malfunction Indicator Light (MIL)
Barometric Pressure		78	Hz

2             Trouble Codes or Fault Codes

2.1       Find where the Codes are listed

 

2.2       Record any codes, and what system and condition they describe in the chart below (Example: might be code number 21, for Throttle Position Sensor, signal voltage too low) If there are no codes listed, put “none”.

Code number	System affected	Condition described
NO CODE

3             Lecturer put in Fault

3.1       Find your lecturer and have him create a fault under the hood (don’t look)

4             Record New Codes

4.1       Look up the codes now in the scan tool

4.2       Record the codes in the chart below. Also record what system is affected, and what condition is described.

Code number	System affected	Condition described
PO113	Intake Air temp	High Input
PO100	MAP	High Input
PO122	TPS	Low Input

5             Find What Data Has Changed

5.1       Look through the scan tool data to see what PIDs (Parameter Identification of system voltages) have changed. Which readings don’t make sense or don’t read what you would expect. Concentrate on the PIDs related to the codes.

5.2       Record the PIDs that have changed below:

Type of information (PID = Parameter Identification)	Letters to describe it	Value of data	Units for data
Throttle Position Sensor	TPS	0v	Volts
Intake Air Temp	IAC	15°C	4.98
Engine Speed	RPM	825	RPM

6             Visual Inspection to find fault

6.1       Do a visual inspection under the hood to find where the problem is. Use information from the code to know where to look for the problem and what type of problem to look for.

Describe problem you found:

When the vacuum sensor is disconneted, the engine stops running.

7             Repair fault

7.1       Plug back in the connector, or repair problem found

7.2       Describe what you did:

Air Temp - 28°C  3.03v
TPS= 0.96v

8             Recheck Data PIDs

8.1       Recheck the data with the scan tool

8.2       Record the voltages for the PIDs related to the problem, to confirm they are back to normal

Type of information (PID = Parameter Identification)	Letters to describe it	Value of data	Units for data
Engine Speed	RPM	825	RPM
Coolant Tempurature Sensor	CTS	90	℃
Throttle Position Sensor	TPS	0	Volts
Intake Air Temp	IAC	15°C	4.98

9             Clear Codes 

Describe what you did to clear codes:

         

           I disconnected of the negative terminal  off the battery and took out  the engine main fuse for 30 seconds

10         Recheck for codes and record codes in system now:

         

 I rechecked the codes by selecting D.T.C, and there was no trouble codes on the screen.        

11      Discuss the importance live data when fault finding

It shows the state of the sensors from the live data values

12      Explain the need for parameters when checking live data

        

          when the fault is resolved, the live data will be rechecked with its parameters then the data should be compared to fault datas.

13     Discuss how a scan tool can aid you when fault finding

         

  I can find the fault easily now and although the vehicle is old or new, I can also check the state of a vehicle with various information.